Electromagnetic switching devices, within the meaning of embodiments of the present invention, include electric contactors, isolating switches, line relays, power switches, etc. In the case of such electromagnetic switching devices, in particular electric contactors, it is necessary in a multiplicity of applications to detect the actual switching state of the electromagnetic switching device—as opposed to a control state of the electromagnetic switching device where applicable—in order to be able to analyze the switching state in another way.
According to the prior art, a detection of the kind takes place by way of a detection apparatus as described above. In this case there is disposed in the housing a mechanical switching contact which changes its switching state when the plunger is transferred from one end position to the other end position. The switching contact is connected to an analysis apparatus via lines, such that the switching position of the switching contact and hence the switching state of the electromagnetic switching device can be detected by the analysis apparatus. The detection apparatus is usually a separate apparatus (called an auxiliary switch) which is different from the switching device.
The prior art approach usually works very well already. It is, though, capable of improvement. In particular, the reliability of the detection apparatus can be increased.